Disk pack cartridge opening and partitioning apparatus

ABSTRACT

A disk pack cartridge opening and partitioning apparatus is described, particularly as adapted for inclusion in disk drive apparatus wherein each cartridge comprises a spreadable jacket containing a pack of compactly stacked, hole-encoded flexible magnetic recording disks. In a preferred embodiment, the apparatus provides means for automatically spreading the jacket followed by partitioning of the stack between a selected pair of adjacent disks.

This is a continuation of application Ser. No. 720,910, filed Sept. 7,1976 which in turn is a division of application Ser. No. 711,628 filedAug. 4, 1976, now U.S. Pat. No. 4,134,143.

BACKGROUND AND FEATURES OF THE INVENTION

This invention relates generally to apparatus for handling diskrecording media and in particular to novel apparatus for opening andpartitioning a cartridge comprising a jacket containing a plurality ofstacked disks.

Workers in the data recording and related record handling arts are wellaware of today's advanced state of the art; e.g., in improved diskrecording media and associated record handling equipment. Such equipmenthas found wide-spread favor, for instance, as related to "flexible" (or"floppy") disks, but heretofore will be recognized as adapted to handleonly single-disk cartridges, as opposed to multi-disk media, (such as astacked array of floppy disks). The present invention is intended tosupplement improved disk handling equipment adapted to handle suchmulti-disk media, providing means to open and separate the jacketcontaining a pack of disks.

In accordance with the invention, flexible (floppy) disks may be stackedand assembled into a "floppy disk pack", as well as retained within aprescribed multi-disk jacket to form a cartridge which may be processedmuch like the well known "single-disk disk" cartridge--this resulting inobvious benefits and advantages. Workers will recognize that such amulti-disk unit record (cartridge) presents certain handling problems;for instance, how to open and spread the enclosing jacket to allow apartition (splitting) of the disk pack and access by a transducerassembly.

A variety of known approaches are illustrated in U.S. Pat. Nos.3,815,150; 3,678,481; 3,668,658; 3,815,150; 3,678,481; and 3,864,755.

The present invention is primarily directed towards apparatus forhandling multi-disk cartridges, especially as adapted for packaging andcontainment of "floppy disk packs" and operation thereof with automaticdisk file equipment. These cartridges are preferably handled tofacilitate insertion into such equipment, as well as accommodating theautomatic opening and spreading of the jacket, the selective rotation ofthe pack therein, and the automatic partitioning of the pack (to exposeany selected disk surface for transducer access and recordingoperations)--these functions preferably being facilitated with minimalmodification of conventional equipment, as described hereinafter. Thepresent invention is intended to provide methods and associated meansfor so opening a multi-disk cartridge and holding it spread during suchpack manipulation.

Workers are well aware that, along with their advantages, "floppy disk"media present certain special problems. Some workers have expressedconcern over whether a "floppy disk pack" could be split andtransducer-accessed in the precise, rapid, repeatable manner that istypically required--especially if housed within the construction of aprotective jacket. This is principally because a floppy substrate seemedso difficult to hold in position and stabilize. That is, while it isadvantageous--and conventional--to house a single-disk in a jacket, andmanipulate it while so centered--it would seen relatively difficult todo so when a multi-disk pack is involved. Finding a simple, practicalmethod and associated apparatus for thus opening such a jacket is animportant object of this invention. This invention is intended toprovide apparatus for incorporation in associated "floppy pack"processing equipment which is adapted to automatically open and spread adisk pack jacket sufficiently to give satisfactory access to atransducer assembly, etc. The present invention is adapted to accomplishthese objectives with automatic equipment which is relatively simple,yet cost-effective, while presenting no danger of damaging or defacingthe jacket or the recording characteristics of the thin plastic disks.

Now, workers dealing with flexible disk media have resorted to specialmeans for packaging the disk, as well as for accessing it. They havetypically provided complex containment structures and associated accessarrangements. It has been found in accordance with the invention thatflexible disks may be stacked directly upon one another in a jacket, yetstill be manipulated within a jacket, held spread-apart, according tothe invention, by means that are relatively simple and conventional--allthis without compromising such characteristic "floppy disk cartridgeadvantages", as compactness, ready transportability, low cost, etc.

With increased use such flexible disk media the "removeability" and"interchangeability" of associated unit records has become increasinglyimportant. Workers are aware that the disk cartridges should be readilyremoved and exchanged to afford greater flexibility and versatility inuse, as compared with a fixed-installation disk, or disk pack--e. g.,the recorded data may be stored "off-line" and read-out later, on call.Also disk cartridges should be processable interchangeably on any driveunit of a certain type. Jacket construction and handling must reflectthis.

Such removeability and mobility of flexible disk media has its price,however; for instance, it typically requires relatively complexcartridge-loading hardware, and elaborate jacket construction (insuringprotection against contamination and for security of data) as well asassociated positioning means (for the accurate, repeatable transducercarriage to any track of and disk). The present invention is directedtoward providing equipment for so handling and opening a cartridge in amanner that can process any cartridge interchangeably, and meets thecited problems and objectives, while still satisfying countervailingobjectives of reasonable cost, relative convenience and simplicity ofimplementation and the like.

The present invention is, moreover, preferably and particularly designedto accommodate a pack of hole-encoded flexible disks as well as thepositioning manipulations associated therewith--more specifically, toprovide pack-partitioning plunger means, and disk selection andtransducer access with automatic equipment.

Workers will recognize that prior art single-disk equipment would beexpected to become relatively complicated when, and if, it is to beadapted for handling a pack of disks. The present invention is designedto meet this contingency in a surprising manner, providing disk handlingequipment which is simple, yet generally compatible with presentsingle-disk equipment and which will nonetheless accommodate flexibledisk packs and associated pack-partitioning means.

It has been found in accordance with the invention that floppy disks maybe stacked and assembled into disk packs, as well as retained within aprescribed multi-disk jacket to form a cartridge which may be processedlike the single-disk disk cartridge--this resulting in obvious benefitsand advantages. Workers will recognize that apparatus adapted to handlesuch multi-disk cartridges would, optimally, employ cartridge handlingequipment that is relatively similar to--and possibly compatiblewith--commonly available single-disk equipment. This invention teaches acartridge-opening arrangement having these desirable features.

Workers will recognize that one of the principle difficulties that arisewhen one deals with a "floppy disk" is its vulnerability to defacement.The typical thin compliant plastic disk pack appears relatively fragileand rather susceptible to damage by some fairly common physicalhazards--such as rupture by impact or sliding contact with a headcarriage, with a "separator knife," or with an accessarm on a diskhandling assembly, or by other sharp edges. Thus, sturdy, yet flexiblejacket construction is necessary. This invention accommodates suchjackets, enabling the quick, simple spreading of the jacket using noneof such prior art techniques and avoiding their hazards.

Now, while the cost of the disk (cartridge) is relativelyinconsequential, the value of the data stored thereon may betremendous--such that if the recording surface is so defaced ordestroyed by such contact that data is lost, the efficiency and securityof an entire associated data processing system may be seriouslyimpaired. The present invention is designed to facilitate the use ofsuch multi-disk flexible media, while yet handling it safely andalleviating, or eliminating, such risks to data integrity. A furtherobject is to effect this by methods, and associated means, which arenonetheless simple, convenient and readily available. Yet a furtherobject is to accomplish this with methods and means that are nonethelesspractically interchangeable with those used for conventional single-diskhandling equipment.

The present invention is further especially designed to accomodate apack of hole-encoded disks, as well as the positioning manipulationsassociated therewith--more specifically, to provide pack-partitioningplunger means, and disk selection and transducer access with automaticequipment.

The present invention overcomes the foregoing and other disadvantages ofprior art structures and methods and provides the mentioned and otherfeatures and advantages according to a novel design.

The foregoing and other features, objects and advantages, according tothe present invention will be more fully appreciated and become moreapparent from consideration of the following description of preferredembodiments of the invention, taken in conjunction with the attacheddrawings wherein like reference symbols denote like parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are schematic plan views of a prior art flexible disk andan associated prior art jacket, respectively;

FIG. 3 is a diagrammatic plan view of a flexible disk modified with ahole-encoding pattern according to the invention, while FIGS. 3A, 3B, 3Cand 3D are like views of alternate arrays of holes (apertures);

FIG. 4 is a schematic diagram of a flexible disk pack embodimentaccording to the invention, with exemplary disks therein shownexploded-away for illustrative purposes;

FIG. 5 is a schematic side perspective of the disk pack embodiment ofFIG. 4 inter-acting with associated pack-partitioning means; while FIG.6 indicates a side view of such an arrangement in operative relationcombination with a turntable and an associated transducer carriageassembly; and FIG. 5A shows a similar, schematic, view of a like diskpack embodiment, including separator disks as well, with severalelements exploded-away for illustration purposes;

FIG. 7 is a plan view of an improved protective jacket, especiallyadapted for disk packs like those in FIGS. 4 and 5, while FIG. 8 showsthis jacket in inverted perspective view and disposed in illustrativeoperative relation with schematically indicated opening means andpartitioning means;

FIG. 9 is a front perspective view of a "disk drive" adapted forhandling disk pack media like the embodiment of FIGS. 4 and 5, as housedin a protective jacket like that in FIGS. 7 and 8, while FIG. 10 is anenlarged close-up view of working elements of this drive, with certainsuperstructure broken-away for clarity of illustration;

FIG. 11 is a schematic side view of a pack partitioning arrangementadapted for use with disk packs like those in FIGS. 4, 5 andparticularly adapted for inclusion in a flexible disk drive like that ofFIGS. 9 and 10; while FIG. 12 is a similar view of an automatic jacketopening means likewise adapted for such a disk pack and suited forincorporation in such a drive; and

FIG. 14 is a schematic perspective view of a pair of mating disk-formingdies adapted to form hole-encoded disks of the type indicated in FIG. 3,these dies being shown in schematic operative relation in the side viewof FIG. 13.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Flexible disks, in general

FIG. 3 schematically illustrates in a preferred embodiment 1 of aflexible (pliant or "floppy" type) disk record adapted, according to theinvention, to be stacked with other like record disks, into a pack asindicated at disk file or stack S in FIGS. 4 and 5. These disks are, asa group and according to the invention, are encoded and arranged to bemanipulated as a group for the selectable partitioning, or splitting, ofthe stack adjacent any selected disk. This is basically accomplished inaccordance with the invention by providing the stacked disks with anencoded arrangement of apertures such that a plurality of uniqueunobstructed paths are provided from at least one end of the stackrespectively terminating at the surfaces of successive disks. Athrusting force applied to a selected one of these unobstructed pathswill then cause the stack to be flexed open between a corresponding pairof adjacent disks in the stack. In the preferred embodiments consideredherein, this is controlled according to the circumferential positionassumed by the pack relative to an associated disk engaging means asdescribed hereinafter.

It is instructive to first consider the design and construction of arelatively conventional floppy disk design 1' as indicated in the priorart FIG. 1. Thus, prior art disk 1' may be understood as a well known"industry-compatible" type of flexible disk particularly adapted foremployment as a unit magnetic data record. Such a disk record will berecognized as comprising a circular flexible substrate of polyethyleneterephthalate or the like having a magnetic coating on at least one sideto thus define a magnetic recording surface. Such disks 1' are adaptedfor protective containment and operation within a jacket, or jacket 3'as indicated by prior art jacket 3' in FIG. 2 within which such a floppydisk may be stored, as well as rotated for magnetic data-transcriptionwhen inserted into appropriate apparatus.

Thus, disk 1' has a central aperture 1'-h for engaging a conventionalrotary-drive spindle (while contained within jacket 3'), there being aprescribed recording track zone 1'-T defined between respective innerand outer track margins 1'-IT, 1'-OT also, an "index hole" 1'-Ih isdisposed (within 1'-IT) along a prescribed "reference radius" AS andadapted to establish a "Start Radius" for the circumferential datatracks as known in the art. Within inner non-recording margin 1'-IT isan inner "contact annulus" defining the locus of engagement withspindle-contact means as known in the art.

Locator-hole array

According to a first feature of novelty, a file of novel flexible disksD-1, D-2, D-3, etc., generally like disk 1, are manufactured as a groupand adapted to include a prescribed array of separating apertures, orlocator holes, L-H, as schematically indicated, for example, by locatorholes L-1, L-2, L-3, etc., in FIGS. 3 and 4. This aperture array will beseen as establishing a certain mode whereby the stacked disks may bepartitioned according to a unique, simple control involving merelyrotating the stack to different (rotational) angular positions, onecorresponding with exposure of a respective one of the disks. Each diskin a file, or stack, S will be understood as having a uniqueidentifiable number of such locator holes L-H so that when the disks aresuperposed with their index holes 1-Ih and their circumferential edgesin registry, they will be seen to represent a hole-encoded array. Thatis, when viewed from one side, the stack will present an array oflocator holes L-H in registry at different circumferential angularlocations about the disk periphery that terminate at successive disks.Thus, each locator hole corresponds to a prescribed select-plunger siteadapted to facilitate the splitting, (i.e., partial-partitioning), ofthe stack to expose the recording surface of a corresponding selecteddisk.

Accordingly, locator holes L-1 pass through all disks and correspond tothe "selection" (exposure of upper surface) of the top disk D-1, holesL-2 correspond to exposure of D-2, terminating at disk D-1 so thatinsertion of a plunger therethrough splits pack S to expose the upperrecording surface of disk D-2--or the lower surface of D-1, holes L-3expose D-3, holes L-10 expose disk D-11, and so on. This hole pattern isunique for each disk, the holes adding cumulatively in one directionalong the pack axis.

Preferably, locator holes L-H are arranged along a circumferential trackor locator locus L-T and spaced a prescribed constant radial distancefrom the disk center and separated by a prescribed constantcircumferential distance, or angular separation (that is, angulardisplacement φ₁₋₂ the same as φ₂₋₃, etc. in FIG. 3). These encodedlocator holes are thus each centered on a prescribed associated radialaxis, e.g., axis A_(X) -1 for hole L-1, A_(X) -2 for hole L-2, etc., theholes being of prescribed identical size and configuration--preferablyelliptical holes (or notches, as discussed below). Thus, as betterillustrated in associated FIG. 4, for instance, when eleven (11) suchflexible disks 1 are superposed in registry, a stack S results,including disks D-1, D-2 through D-11 disposed for co-rotation by acommon spindle (not shown here, but well known, and schematicallyindicated in FIG. 6 and described below). The pattern of locator holeswill be such as to provide the mentioned hole-encoding and enabling aprescribed mode of partition.

Thus, for instance, the topmost disk D-1 in the stack is arranged tohave a single hole L-1, while the second disk D-2 is arranged to haveone additional locator hole L-2 (besides L-1) disposed along an initialaxis A_(X) -2; the third disk D-3 in the stack in turn arranged to haveidentical locator holes L-1, L-2 (as disk D-2) together with one addedlocator hole L-3 (distinguishing it from D-2, D-1 and all other disks instack S) aligned along axis A_(X) -3 and along circumferential axis L-T,A_(X) -3 being angularly displaced from A_(X) -2 by a prescribedconstant angle. The fourth disk D-4 is accordingly likewise cumulativelyencoded with locator holes L-1 and L-2 in registry with these holes onD-3, together with an added hole L-4 along axis A_(X) -4 uniquelyidentifying this disk and spaced along track L-T and angularly displacedfrom axis A_(X) -3 by the same prescribed amount φ₁₋₂ =φ₂₋₃ (for example18°). Eleventh disk D-11 is similarly encoded according to the samepattern, its locator holes L-1 through L-10 being a duplicate of theseof adjacent disk D-10 with hole L-11 being added as indicated, andlikewise for other disks in the pack. This hole-encoding will generate acoordinated stack of flexible disks which is arranged so that insertionof a separating plunger at a prescribed angular orientation (e.g., alongtrack L-T, at a selected increment from the "Start Radius" AS) candeflect an appropriate sub-group of disks aside to create the desiredstack partition for transducer access and engagement with the selected,corresponding disk surface, as illustrated in FIGS. 5 and 6.

This operation will be better understood by consideration of FIGS. 5 and6 where stack S is shown engaged upon a turntable TT with the disk hubssuitably engaged (e.g, pressed thereon by spindle clamp SC) againstrotatable spindle hub S-H as known in the art. A plunger, or disk-selectmeans P will be disposed nearby, being located generally along the"cylindrical locus" including locator track L-T such as to beselectively insertable up through track L-T a prescribed excursion--andthereby split pack S for "transducer access" by transducer assembly 117(FIG. 6). Assembly 117 comprises a carriage including arm 11 carryingtransducer head 15 and threadedly engaged at barrel 118, for lateraltranslation (into pack S as known--arrow) by rotation of lead screw 112.Motor 111 is coupled to rotate screw 112 and controlled in a knownmanner to effect this pack-insertion at prescribed times. Thus,transducer 15 is generally thrust toward, or away, from pack S asindicated and known in the art so that any given (upper) disk surfacemay be accessed and operated upon.

Thus, in the illustrated arrangement of FIGS. 5 and 6, the upper surfaceof disk D-3 will be understood as "selected" for access by transducer 15with overlying disks D-1 and D-2 being thrust upwards and away byplunger P as shown. Accordingly, (and understanding the hole-encoding tobe as indicated in FIGS. 3 and 4 above) for selection of D-3, pack Swill be angularly rotated with respect to the "thrust-path" T_(p) ofplunger P (indication by phantom outline) to bring it into registry withselected locator hole L-3. Now, when plunger P is actuated to be thrustupward, it will pass through holes L-3 provided in all disks D in thestack S except for disks D-2 and D-1 (which have no L-3 holes)--and thiswill thrust D-2 and D-1 upwards (as indicated in FIGS. 5 and 6) to aprescribed partial-partitioned condition. This will allow entry ofaccess arm 11, and particularly of shroud 13 on the distal end thereof.As further discussed below, plunger P is then retracted with shroud 13then providing supporting engagement with (the lower surface of) diskD-2 during stack rotation. In this way, disks D-1, D-2 may be helddeflected-away while pack S is rotated and head 15 is engaged on D-3 fora transducing operation.

According to a further feature, shroud 13 is arranged to smoothly engagesuch a deflected disk--bending all deflected disks over head 15 as thepack is rotated (within its jacket); also allowing the assembly 117 tobe thrust a greater or lesser extent into the stack for translatingtransducer 15 between various recording tracks on a selected disk.

Similarly, if disk D-2 is next "selected" for transducer operations,transducer mount 117 will be withdrawn, and the rotation of stack Sinterrupted, with the stack being oriented (as discussed below) to alignlocator hole L-2 (associated with selection of D-2) above plunger P sothat upward thrust of the plunger the same prescribed distance as beforewill pass it through the registering locator holes L-2 in all disksexcept uppermost disk D-1--which has no L-2 hole and accordingly will bethrust into the approximate location of disk D-2 in FIG. 6. This willthen allow the re-introduction of the access arm 11, i.e., of shroud 13which will then be engaged with the under-side of D-1, so that, with thesubsequent retraction of plunger P, stack S may again be rotated toinitiate transducer operations upon this selected recording surface(upper face of disk D-2). FIG. 5 indicates, in schematic perspectiveview, the same upward thrusting of disks D-1 and D-2 and splitting ofstack S as indicated in the side sectional view of FIG. 6, with thedisks flexing and bending along a prescribed portion thereof (FL) underthe upward thrust of the plunger.

Partition Method

It will be evident that such a partitioning mode involves the simplerotation of the pack relative to the plunger, i.e., to angularorientation registering select-site therewith. Workers will perceivevarious ways of effecting this. Preferably in this embodiment, for eachpartition cycle (i.e., associated with exposure of each disk), the packis brought to the reference orientation [i.e., rotating to align "StartRadius" with the plunge path] and then advanced by the number ofsuccessive select-sites required to register the proper site (i.e.,corresponding to the particular disk "selected") with the plungerpath--preferably doing so digitally.

Table I below summarizes preferred exemplary dimensions andcharacteristics of this floppy disk embodiment and associated disk packmentioned above:

                  TABLE I                                                         ______________________________________                                        (FIGS. 1-6)                                                                   ______________________________________                                        Disk material:                                                                          3 mil (nominal) polyethylene terephthalate                                    with burnished magnetic oxide coating                                         (randomly oriented Fe.sub.3 O.sub.2) on both sides.                           Max. coeff. of expansion:                                                     Thermal: 9 × 10.sup.-6 in./in./° F.                              Hygroscopic: 11 × 10.sup.-6 in./in./%RH;                      Disk diameter:                                                                          7.88"; recording between 4.06" (track no.                                     "7b") and                                                                     7.23" (track no. "00") radii;                                       --        index aperture (1-Ih): 0.302" in diam.;                                       at 1.7-2 inches radially out from disk                                        center.                                                             --        "IBM compatible" format [see AN std.                                          document no. 388/75-23 for a flexible                                         cartridge apt for operation at 50-125° F.                              temperature and 8-80% relative humidity].                           Locator holes                                                                 (L-H):    spaced on 18° centers, along L-H locus at                              7.5-7.6" diameter and about 0.156" in                                         diameter (for 93 mil plunger rod), with                                       hole spread of about 3.6°                                    ______________________________________                                    

Recording Characteristics

With a conventional (ferrite-core) magnetic Read/Write head lightlyloaded against the recording zone of a selected subject disk, mountedatop an opposing contact pad, provided conventionally (e.g., as on theBurroughs No. 2027-1441 Flexible Disk Drive, for example), the recordingand other characteristics will be generally as known in the art exceptwhere otherwise stated.

The described flexible disks may be expected to exhibit verysatisfactory resistance to wear and abrasion as understood in the art(e.g., after about one-million wear revolutions on any one track signalamplitude of an "all double-frequency recording" should have no bitsexhibiting less than about 75% of the initially recorded signalamplitude). The subject disks are best adapted for "soft sector" formatrecording (as opposed to the "hard sector", or perforation-designatedformat, known in the art), the index pulses being generated and sensedwithout resort to more than a single index aperture.

Now, as those skilled in the art will appreciate, improved flexiblerecording disks of the type described will lend themselves to many formsof data recording and especially magnetic recording. For instance, withthe familiar array of concentric magnetic recording tracks, it may bedesired to employ a clocking means such as a separately-recorded clocktrack with its own separate transducer, or alternatively a separateclock track disk can be incorporated into each pack as known in the art.On the other hand, known techniques may be used which require noseparate timing track, for example, inserting a "parity bit" atpredetermined locations along each data track or using a recording modewhich is "self-clocking".

Various alternate configurations and materials will occur to thoseskilled in the art, such as the use of chromium oxide or like magneticcoating or the use of acetate or like flexible substrate material, orthe arrangement of locator holes in different patterns and/or shapes asdiscussed below.

Alternate Locator-aperture Configurations

The locator holes L-H need not be elliptical but may instead be circularas indicated in FIG. 3-C, rather then being elongated along the locatoraxis L-T sufficient to accommodate contemplated variations inlocator-rod positioning relative to the disk stack, as is indicated inFIG. 3. Disk D' in FIG. 3-C is generally the same as the disk 1 in FIG.3, except that the locator holes L'-1 and L'-2 are extended in theirelongate direction along axis L-T to be roughly twice as long, withrounded edges, (preferred: about 0.16×0.3 inches).

As a further alternative, the locator apertures may comprise "notches"rather than "holes" as indicated in FIG. 3-D for alternate diskembodiment D". Disk D" is generally the same as disk 1 in FIG. 3 exceptthat the locator holes here comprise a pair of rather semi-ellipticaledge notches L"-1 and L"-2. Workers in the art will conceive other likemodifications, for instance, where the entire periphery of the disk is"cut-out" between all locator holes--such as by cutting out the "lands"between L"-1 and L"-2 in FIG. 3-D. Alternatively, the disk periphery maybe cut-back within the hole peripheries except for "sector-lands"extending radially from the disk, forming extended circumferential"tabs" adapted to engage select-rods--being disposed entirely about thedisk except where the locator holes would have existed (and between suchlocator sites as well). Of course, the size and configuration of alocator aperture will generally correspond to that required toaccommodate a given partitioning-plunger (shape, diameter) configurationand consistent along with the positioning accuracy of the associated"select-partitioning" system. Such a "tab-select" arrangement will bebetter adapted for relatively rigid disks.

Multiple "partition-plungers"; "paired" locator holes

Further, according to a modified feature of the invention, indicatedfunctionally in FIG. 3A, a plurality of such "partition-plunger means"(rather than a single plunger) may be used, together with associatedplural sets of accommodating locator-holes. Thus, a modified embodiment101 (identical to disk 1 in FIG. 3 except as otherwise described) willbe seen as including "locator-sectors" characterized by a pair oflocator holes A and B symmetrically flanking each "locator axis" andequidistant therefrom. With such a modified "double-hole" locatorpattern, disk 101 will thus be understood as intended for use with apair of partitioning plunger rods, each similar to that described inconnection with FIGS. 5, 6 and 11, except that two rods (rather thanone) are used to deflect the pack (--such a pair being more fullydescribed below in connection with FIG. 12).

Thus, for instance, rather than a single select hole (e.g., L-1, FIG. 3)being centered in a "first locator sector" along the "first selectorradius", A_(X) -1, the so-modified flexible disk embodiment 101 (FIG.3A) substitutes a pair of such holes (L-1A, L-1B), each displaced fromthis axis A_(X) -1, on opposite sides along locator track L-T, by thesame angle φ (i.e., symmetrically flanking their associated selectorradius). Similarly, the second locator sector and its radius A_(X) -2serve to reference two "select apertures" (rather than one), namelyL-2A, L-2B; likewise for the "third" select radius A_(X) -3 about whicha pair of associated select apertures L-3A, L-3B are symmetricallyflanked.

Thus, for example (and as more fully described below), when the flexibledisk (D-4) next to disk 101 (assume as D-3), in an associated stack isto be "selected" for Read/Write operations, the stack will bepartitioned by the pair of locator rods--the rods being moved intoregistry with associated locator holes L-4A, L-4B (shown in phantomhere) flanking the "fourth" select radius A_(X) -4. Then, when theserods are thrust upward in the "standard" manner, disk 101 (i.e., D-3)along with the first and second in the stack (i.e., D-1, D-2) will belifted upwardly to expose the upper recording surface of D-4.

Up/down selection mode, with opposed plunger pairs and "stripping" ofselected disk

FIG. 3B indicates how a pair of associated select plunger means areadapted to "opposingly partition", i.e., are driven in oppositedirections, so that, to the upward partitioning-thrust there is added asecond contemporaneous downward, partitioning-thrust in each partitionoperation. As workers can see this added down-thrust can "strip" the"selected" disk from the upwardly-thrust stack portion--more positivelyand more quickly--and prevent it from being accidentally carried-up withit (e.g., adhering via suction or static electricity, etc.). Further,such a "paired-sites/alternate hole" array of locator holes is providedto accommodate this "opposed partitioning" mode. Modified diskembodiment 201 in FIG. 3B illustrates this schematically (beingidentical to embodiment 101 in FIG. 3A, except that each "companionhole" is provided on "non-selected" disks in a pack not as otherwisedescribed) exemplifying a pair of select-hole "sites" in each sector.The site pairs flank their associated select-radius A_(X) in equidistantsymmetry; however, with only one hole in each such pair actually cutthrough at any sector--and "up-holes" at only through disks to bedeflected; "down-holes" through all others. This hole-pattern will beseen as accommodating the "opposed-partitioning" mode described.

Thus, for instance, disk 201 may be viewed as constituting the fourthdisk (from the top) in a stack (much in the manner of embodiment 101 inFIG. 3A), with each of its select radii A_(X) flanked symmetrically by apair of such (up/down) "select sites", (e.g., an upward-select hole cutat L-1U, and downward select "site" L-1D, there being no "hole" cut at"down site" L-1D here--both these hole-sites being found in the "firstsector", symmetrically flanking the "first" select axis A_(X) -1).

This "paired site/single hole" pattern of locator-holes will beunderstood as functioning to provide each disk in a given stack withone, and only one, select hole cut in each and every one of its "selectsectors". Thus, for any given disk in a given stack, there will be onesuch locator hole (but only one) cut in each sector--with "up" holes cutin the disks own "select sector" (e.g., sector "four" for disk D-4) andin all the "lower-order" sectors (corresponding to the number of disks"below" the given disk, e.g., D-1, D-2, D-3 "below" selected disk D-4);whereas, conversely, "down" holes are cut in all other disks ("higherorder") at this sector. For example, for disk 201, or D-4, in a 20-diskpack, "up-holes" L-1U, L-2U, L-3U and L-4U are cut only for the firstfour sectors, with "down" holes cut for all other, "higher-order",sectors in disk D-4 (i.e., L-5D, L-6D through L-20D). Similarly, the"topmost" disk (D-1) has an "up-hole" cut only at its first sector(adjacent axis A_(X) -1) with all other holes being "down-holes".

Hence, in the selection of the "first" (i.e., top) disk D-1 in a stack,associated with disk 201, the upward thrusting select-plunger will beunderstood to pass through all disks (through "up holes" L-1U in thefirst sector of all disks including D-1), while the downward-thrustingplunger will pass through "no disks", but merely thrust D-1 downwardly.Or, for the selection of the next (i.e., second) disk, D-2, in thisstack, the "up plunger" will pass through all disks except D-1 (throughall "up" holes in the second sector of D-2 to D-n), and so deflect D-1to expose D-2, while the "down plunger" will pass only through disk D-1to "strip away" D-2, pushing it downward. Or, in the selection of thethird disk, D-3, the "up" plunger will pass through disks D-3 to D-n(L-1U holes therein), while the "down" plunger will pass through disksD-1 and D-2 only (L-1D holes therein)--so on and so forth.

Now, a "paired" array of locator holes as above described (such as inFIG. 3A) need not, in all cases, imply the symmetry of hole locationdescribed and illustrated (i.e., symmetrical flanking of given selectaxis). But such symmetry is preferred. For instance, it affords anextraordinary, unexpected advantage in event of "double side" recordingwhereby the disk stack may be "flipped" (turned upside-down) and stillbe partitioned with a plunger pair, without any change in the relativepositioning or the operating mode of the plunger arrangement. Workers inthe art will perceive this to be a very significant advantage andconvenience.

Workers will perceive other advantages accruing from the foregoing novelhole-encoded flexible disk design according to the invention. One suchadvantage is that it is compatible with the bulk of present dayrecording disk media, as well as with known equipment for handling suchdisks--thus being adapted for use, interchangeably, with conventionalfloppy disks where desired. For instance, the existence and pattern ofthe peripheral locator hole pattern need not interfere with, or changein any way, the operation or construction of a conventional(single-disk) drive and Read/Write assembly. Also, as indicated, thedisk is adapted for mounting on standard flexible disk turntables fortransducing rotation and for relatively conventional transducer accessand engagement. Further, such an improved flexible disk may be combinedwith conventional (single-disk) protective jackets, as indicated belowand in FIG. 2. Moreover, workers will recognize that a "hole-encoding"scheme such as employed herein for flexible disks may, in certaininstances, be adapted for rigid, or semi-rigid disks as well.

Novel disk pack

According to a principal feature of the invention, improved flexibledisks like those described above are apt for coordination and stackingtogether in combination in a novel "flexible disk pack", as indicated,for instance, in FIGS. 4 through 6. It will be evident, of course, thatthe pattern of locator holes (whether single or double pattern) will becoordinated in the usual case with a particular stack in mind, the stackbeing comprised of certain number of such disks, with each disk in thestack having its own unique variation in the (common) pattern of locatorholes. Thus, as more fully described below, one may manufacture thesedisks in sets for efficiency and convenience sake. For instance, one maypunch-out a set of "first" (i.e., D-1) disks, then a set of "second"(D-2) disks and so forth; the disk packs being each assembled thereafterby collating one each from the D-1, D-2, D-3, etc., sets, up to aprescribed total number (D-n) in the pack. As a feature of conveniencethe disk total may be left somewhat "open-ended" and variable, so thatdisks may be added at any time after a pack is first assembled.

Manufacturers will find it particularly convenient to manufactureflexible disks according to the invention by relatively convenientinexpensive means, such as in a cutting-out or stamping operation asdetailed below. For instance, a die press arrangement of the type knownfor working with such polymer sheets may be made up to cut the "D-1"disk pattern; then it may be modified very slightly to cut the "D-2"disk pattern, then modified again for the "D-3" disk pattern, etc. (seeEx. 1 below). Alternatively, in the case of the "double set" of locatorholes described above, a similar, but modified, convenient mode of diskfabrication may be followed.

Preferably, and according to another feature, when such a disk pack isassembled, the disks are bonded to one another at bond sites dispensedalong a common registering circumference, adjacent the disk center, andspaced radially therefrom to lie in the inner "non-recording" band.Thus, a circular array of "epoxy pillars" B-L is indicated as thebonding sites in FIGS. 3 and 5, to constitute such a pack bonding means,whereby each pillar B (FIG. 5) is comprised of epoxy. This epoxy isintroduced in a viscous liquid form to fill a number of particularregistering sets of bores, one bore through each disk constituting aset. Once the stack has been assembled, with the disks positioned sothat their corresponding apertures and bores lie in registry, suchbond-fillings may be applied together. The viscous epoxy fill, in theusual case, spreads down the bore tunnel and somewhat beyond theperiphery of each bore, to lodge between superposed disks and thenharden to form a clamping "pillar". This "adhesive pillar" will hold thedisks together as assembled in the stack and keep them from lifting awayfrom one another and from being rotated into mis-registration with oneanother.

Workers will contemplate alternate bonding techniques. For instance, onemight interpose an annular spacer between disks in a pack and providethem with adhesive surfaces adapted to adhere to the upper and lowerdisk thereby bonding them together. In another technique, wherecontemplated disk cycle and handling allow, one might insert pinsthrough each set of bonding bores and cap their ends, thus preventingmisalignment in the radial and circumferential sense (also, perhaps,allowing prescribed axial freedom to better accommodate packpartitioning).

Workers in the art will recognize that such a permanently bondedflexible disk pack is new in the art and is uniquely well adapted formany desirable functions, such as the hole-encoded disk selectionoperations (described elsewhere), as well as for containment andoperation of the pack--as a whole--within a protective jacket (asdescribed below). Thus, workers may now contemplate the use of amulti-disk flexible pack as a multi-surface unit record which is almostas lightweight, as compact and as easy to manipulate, store, transport,etc. as a single disk, while having many times its storage capacity.

By way of illustration, it has been found that a pack of 20 flexibledisks according to the invention (e.g., as in FIG. 3 and Table I), eachwith a nominal 3 mil thickness, can be used in a "floppy disk pack"presenting a composite thickness of little more than 60 mils and, rathersurprisingly, may be readily packaged and operated in a protectivejacket similar to the prior art jacket indicated in FIG. 2. Further,such a pack may be manipulated and operated inside this jacket with diskdrive equipment that requires relatively little modification over theconventional single-disk drives known in the art.

Liners

FIG. 5A indicates a similar pack of flexible disks, D-1 through D-n,understood as bonded together in fixed, registering superposition toform a single unitary multi-disk pack ST. This pack is, however,somewhat modified, according to a further improvement feature, toinclude protective flexible spacers, or "liners" (SL) interleavedbetween adjacent disks in the pack. More particularly, FIG. 5A shows theupper two flexible disks, D-1 and D-2, exploded-away from stack ST forillustrative purposes, and indicates the protective liner means in theform of flexible plastic disks, SL-1 and SL-2, interposed betweenD-1/D-2 and between D-2/D-3, respectively.

Preferably (and mostly for convenience), liners SL are comprised of thesame (or a closely similar) flexible plastic material as the disksubstrates, but of course, will preferably carry no magnetic coating. Ithas been found that confronting oxide-coated sheets in certainembodiments may be rubbed or scraped against one another such as to"scour" or gall magnetic oxide from one to the other. For instance, thismay occur with a novel flexible disk pack during partitioning, etc., andcan be damaging.

According to this feature, liners S may be provided to protect everyoxide surface, preferably being bonded together along with the disksinto a unitary pack. Liners SL include an index hole I-h in registrywith that of the disks D, as well as a locator hole pattern identicalwith that of the adjacent disk and in registry therewith. As to the"up-holes" (e.g., L-1U illustrated in SL-1--i.e., adapted for the "up"select/partitioning arrangement represented by the disk embodiment inFIG. 3), it will be understood that a liner's locator hole pattern willbe identical to that of its adjacent superposed disk (here disk D-2 forliner SL-2, D-1 for SL-1). For embodiments also including "down-holes"(as in the embodiment of FIG. 3B) the down-hole pattern of a liner willfollow that of its superposed disk (so a liner will never intervenebetween a transducer and exposed disk). Thus, the spacers, or liners SL,may for instance, comprise a clear polyester, such as polyethyleneterephthalate (e.g., a white "Melanex", trade name of ICI) about 1-2mils thick, or a similar thin flexible material with a low friction,"non-galling", anti-wear surface (or surface coating). Liners will beespecially useful where contemplated pack life/usage is to be extendedand the associated pack enlargement can be tolerated.

Alternate liner materials may of course be used as contemplated byworkers in the art, the thickness and other characteristics thereofbeing modified to suit the requirements of a particular application.While not necessary in every application the use of such liners ispreferred in cases where one or both magnetic recording surfaces of aflexible disk, so bonded into a flexible disk pack, exhibit wear andabrasion problems.

Of course, alternative to using liners SL, the stacked disks D may haveone side thereof coated with a protective film, shielding it from suchadverse contact with a facing magnetic recording surface (e.g., acoating of one to several mils of clear plastic such as "Black Watch" by3M Co.) or the plastic substrate may be left uncoated by any magneticoxide or by any similar coating. Of course, as workers in the art know,flexible disk manufacturers prefer to coat both disk sides with amagnetic oxide for their own manufacturing convenience, and to preventcurl.

EXAMPLE 1 Manufacture of Hole-Encoded Flexible Disks p Workers in thisart will visualize various practical ways in which hole-encoded flexibledisk records of the type described may be manufactured. One such methodis schematically indicated in FIGS. 13 and 14 and involves a die press,or punch, arrangement particularly apt for punching-out all the severalapertures of disk embodiments like those described above. By way ofexample and according to an associated feature, it will be seen thatsuch a disk manufacturing arrangement is intended to punch-out a"family" of related flexible disks (like disk embodiment D-1, D-2, D-3,etc., in FIG. 4) adapted for coordinate assembly and operation in abonded pack like that described, using relatively conventional means andmethods.

According to a further feature, this stamping arrangement may also bereadily modified, by means well known in the art, to inexpensively andconveniently manufacture all the different successive-numbered disks ina pack--each with its unique modification of the select-hole pattern,using, essentially, a single press with simple die modifications. Forinstance, one may, according to this feature, manufacture 1,000identical hole-encoded packs, each comprised of eleven differentflexible disks (D-1 through D-11) by first using the arrangement topress out 1,000 identical "first" disks (D-1); then, with a slightmodification (described below and using the same process) manufacture1,000 D-2 disks, then with a further slight modification manufacture1,000 D-3 disks, etc.--through D-11. Thereafter, 1,000 packs may becollated and bonded from these.

Accordingly, it will be readily understood that if one starts with acircular disk design having the standard outline configuration (i.e., ofdisk 1 in FIG. 3), this stamping operation will basically function topunch holes of the proper dimension and location for the spindle, forthe index hole, for the bonding apertures, and for the selected patternof locator holes--these last being variable according to the disknumber, or hierarchy, in the contemplated pack. Also, the disk peripherymight then be cut also.

Thus, for example, a flexible sheet of polyethylene terephthalate about3 mils in (nominal) thickness, and having the mentioned circularconfiguration (e.g., diameter of about 14 inches) may be disposed withina concave, cuplike bottom die member D-B, held in a press fixture to beimpressed by a mating press member D-A, adapted to impress the sheetonto D-B and cut out all apertures in one pressing stroke. Thus, pressplate D-A is adapted to be superposed atop a plastic disk so located inD-B and be pressed downwardly by suitable pressing means (known in theart and not shown, but indicated schematically in FIG. 13 at press P),to thereby form the indicated pattern of apertures, punching-out theappropriate segments of this plastic sheet (note the shards SHindicating this in FIG. 13). Except as otherwise described hereinafter,this operation will be understood as being conducted as known by workersin the art from work with similar conventional methods.

More particularly, the cuplike die D-B, understood as the "female die,"is provided with apertures of the appropriate size and location; namelyapertures for: the spindle hole 143', and for the (entire, 11-hole)pattern of locator holes 141', these apertures in die D-B being adaptedto receive and mate with corresponding registered protuberances on therelated "male" press die D-A, selectively (when such are present), so asto cut out portions of the plastic disk and thus form the mentioned diskapertures.

Thus, die-press D-A is correspondingly formed with projecting plugs, orpressing protuberance members, understood as, each, adapted to interfit"cuttingly" with an associated congruent one of the mentioned aperturesin die D-B, being of the same relative cross-sectional size andoccupying the same position. Disk D-B thus comprises a spindle plug 143,and index plug 144, an array of bonding points or plugs 142, and avariable array of "selectively removable" locator plugs P.

Locator plugs P are, as schematically indicated in FIG. 14, to beunderstood as, preferably and according to an improvement feature,selectively insertable into a receiving bore and held there for a givenpressing operation--being apt for removal thereafter, at will, to formany desired variation in the locator hole pattern. Thus, for instance,die-press D-A will be understood in FIG. 14 as illustratively indicatingthe insertion of three locator plugs 145 (i.e., plugs P-1, P-2, P-3)into receiving bores positioned and dimensioned to make the cuts forminglocator holes L-1, L-2 and L-3 respectively in disk 1 in FIG. 3 (alongwith the other associated holes for indexing spindle and bonding, asbefore indicated). These plugs may be held in these bores by suitablemeans (not shown) or may constitute any other like arrangement (known inthe art but not illustrated).

Workers in the art can readily visualize that, in any given pressingrun, one, or several, circular plastic disks may be so impressed to beformed with the pattern of apertures represented by die-press D-A andthat this die-press may thereafter be modified by addition, or removal,of locator plugs 145 to press-out another disk which is identical exceptfor a modified locator hole pattern. For instance, after pressing of asuitable number of D-3 disks with the arrangement of locator plugs 145indicated in FIG. 14, another locator plug P-4 (not shown) may be addedto stamp out "D-4" disks, etc. Of course, the "lower order" disks D-1and D-2 may be formed by removing P-3 and then also P-2 respectively.Thus, it should be apparent to workers skilled in the art that accordingto this feature, with this or any similar stamping operation, stacks ofhole-encoded disks of the type described may be very inexpensively andconveniently produced.

Associated jacket embodiment

Novel disk pack embodiments like those above described will beunderstood by workers to be particularly apt for advantageous use in theform of a cartridge, i.e., the resulting structure obtained when thedisk pack is employed in conjunction with a protective jacket structurein which the disk pack remains during partitioning and transducingoperations. Such a jacket 21 is indicated, for instance, in FIGS. 7 and8, being designed somewhat along the lines of a prior art, single-diskjacket 3' (FIG. 2), but modified for the purposes of the presentinvention as illustrated in FIGS. 7 and 8. Jacket 21 is shown in plan"bottom" view in FIG. 7; and is shown, in "top" perspective view, inFIG. 8 as cooperated with jacket-opening means, schematically shown inconjunction therewith and functioning as described below. Such amodified jacket will be perceived as especially suited for housing arotatable pack of flexible disks, like pack S in FIG. 5, being apt foraccommodating the rotation thereof, in situ, as well as for the locatorhole partitioning mode and associated transducer access described above.

Thus, referring to FIGS. 7 and 8, jacket 21 comprises a pair of opposed,relatively flexible panels, namely top panel 21-T and bottom panel 21-B,joined together, along a closed end as well as along about one-half ofthe two adjacent sides by means of flaps f-1, f-2 and f-3 shownextending in partly assembled fashion from top 21-T in FIG. 8, and shownfolded-over and joined to the edges of top panel 21-T in FIG. 7. Panels21-T, 21-B may be comprised of PVC (polyvinyl chloride of about 10 milsnominal thickness), or like material, known to workers in the art.

It will thus be understood that these top and bottom jacket panels 21-Tand 21-B are preferably joined by folding over flaps f-1, f-2 and f-3 soas to permit their being spaced apart sufficiently to form an entry slot21-O for admitting a flexible disk pack of prescribed diameter andthickness, such as shown in FIG. 5. Jacket 21 will have conventionalapertures corresponding to the spindle hub and index hole (21-H, 21-I,respectively, but slightly enlarged therefrom), as well as having twopairs of "spreading-rod apertures" (up-spreader-apertures 22 throughbase panel 21-B, and "down-spreader apertures" 23 through top panel21-T), to accommodate the upper and lower jacket spreading means,according to the invention (see in phantom FIG. 8). Illustrative pack Sis shown outlined in phantom in FIG. 7. Spreading is preferably doneautomatically when the so-formed cartridge (jacket 21 containing diskpack S) is inserted into a disk drive, (FIGS. 9 and 10) this beingindicated schematically by the up-thrusting plungers 31 and thedown-thrusting plungers 33 in FIG. 8, according to another feature.Down-plungers 33 are preferably also arranged to pin the jacket to afixed portion of the chassis to hold it fixed with respect thereto whenthe pack is rotated therein. Preferably the "spreading action" of theseplungers is automatically invoked by closing of the entry door of thedrive apparatus after admission of the pack-containing jacket (FIG. 9).It will thus be apparent that the two opposed (upper and lower)"spreader means" 31 and 33 act in concert to separate the outer edges ofthe "entry slot" 21-O when the disk pack is to be "accessed" by atransducer assembly (FIG. 6).

Retainer means such as tabs 24 are also preferably provided withinjacket 21 to retain the disk pack, removably, in prescribed positiontherewithin. These retainer tabs 24 preferably comprise a suitablenumber of upper and lower inwardly-projecting members projectingnormally inward from the top and/or bottom panels adjacent entry-slotS-O and "following" the periphery of the pack as positioned withinjacket 21. This is indicated schematically in FIGS. 7 and 8.

An "entry flap" 21-F is formed of the "outer-half" of top panel 21-T, asschematically indicated in FIG. 8. Flap 21-F is adapted to be pivotedaway from lower panel 21-B, along a prescribed flexing axis F-A_(X) soas to provide an entry slot 21-O sufficient to accommodate thepartitioning of the pack within the jacket as well as the related entryof the transducer assembly, as illustrated in FIG. 6. Preferably, thispivoting flap 21-F is held closed, to retain and protect the containeddisk pack by suitable "spring return" means, either in the form of panelmaterial which is suitably stiff and/or with a stiffening "return-wire"21-W embedded along the periphery of the flap as indicated schematicallyin FIGS. 7 and 8. In extreme cases, return springs may be providedacross slot 21-O.

Jacket 21 also has a slot 21-SL in base panel 21-B to accommodateengagement of the enclosed flexible disk pack (specifically the "bottom"disk thereof) with a transducer "contact pad" (CP) (see FIG. 6) when aRead/Write head is impressed upon (one or several disks in) the pack,opposingly, as known in the art. Similarly, bottom panel 21-B is alsoprovided with an elliptical locator aperture 21-LI adapted for admittinga select-partitioning plunger of the type described above andillustrated in FIG. 5 and elsewhere.

Jacket 21 and the flexible disk pack contained therein thus comprise anovel flexible disk cartridge, with the pack so positioned and heldtherewithin as to be free to rotate, as well as to be selectivelypartitioned and accessed therein as previously described. Jacket 21 ispreferably lined with a non-shedding, non-abrasive cleansing tissue onits inner faces as known in the art, to wipe clean and protect the outersurfaces of the disk pack contacted thereby.

Modified drive for flexible disk pack

FIGS. 9 and 10 show in a relatively conventional type of flexible diskdrive 100 which has been modified to accommodate operation with novelcartridges (jacketed flexible disk packs) according to the invention.That is, drive unit 100 will be understood by workers in the art tocomprise a compact, portable, disk drive device that interfaces with acentral processor portion of a data processing system by way of asuitable control unit (not shown), as known in the art.

Thus, such a modified disk drive as shown in FIGS. 9 and 11, whileotherwise constructed and operating as known in the art, will beunderstood to include modifications required in order to makeadvantageous use of the novel disk pack and jacket of the presentinvention, such as, for example: jacket-opening spreading means (FIGS.7, 8 and 12); pack rotation (vs. disk rotation) means (FIG. 6); packpartitioning means (FIGS. 3, 6 and 11) and an associated transducerassembly (FIG. 6). The pack-rotating spindle will be understood as beingcontrolled to rotate the pack to any one of several angular orientations(one associated with each disk in the pack) for partitioning, and ispreferably operated with a motor adapted to be stepped by prescribedprecise constant increments, representing digital control signals, thusfacilitating precise digital control to step the pack by precise angularincrements between such orientations for partitioning.

The jacket or cartridge J (identified by numeral 21 in FIGS. 7 and 8) isadapted for insertion into unit 100, as indicated in FIG. 9, through apivotable "access door" 110 to be thrust in prescribed alignment along aprescribed reference plane defined by left and right side guideways105-R, 105-L, and forward working platform segments 125, 125', 125" tobe positioned against stops 100-S, 100-S' (FIG. 10). With jacket J thusdisposed in "working position", an extended contact pad 117 will beregistered with jacket slot J-S and the disk pack S within the jacketwill be positioned so that its inner contact zone may be engaged forrotation between a lower rotatable spindle 109-A and an upperexpansible-cone, or hub 109 (FIG. 10) adapted to be driven in idlerfashion by spindle 109-A when clamped down on the pack, fitting into thehollow center of spindle 109-A, as well as known in the art. Hub 109(FIG. 10) is freely rotatable and is suspended on a clamp arm 107 of apivotable subassembly 136 so as to be pivotable into engagingrotary-driven relation with the so-injected pack holding it on spindle109-A. This engagement is preferably automatically invoked upon theclosing of door 110 as known in the art, with a drive motor 121 beingstarted and coupled (e.g., through a belt drive, etc.) to rotate spindle109-A at "transducing speed" (for example 360 rpm).

The major components of drive unit 100 thus comprise a transduceraccessing arrangement 115, (e.g., including transducer carriage 117 andtranslation motor 111 of FIG. 6), a pack-partitioning subassembly 140including plunger P projectable through a bore in surface 125 (see FIG.11), a jacket-spreading subassembly 150 including a pair of up-plungers31-A and 31-B (FIGS. 9 and 10) projectable through bores in surfaces125', 125", (see also FIG. 12), and the mentioned rotary drivesubassembly 120 (comprising spindle motor 121, spindle 109-A and hub 109mounted on pivot-arm 107), the entire assemblage being mounted upon achassis 103. These mechanisms will be understood as constructed andoperated in a known fashion except as otherwise described.

Thus, transducer subassembly 115 comprises a Read/Write head unit, ormount 117, normally disposed just beyond the pack and adapted to beprojected inward as discussed re FIG. 6, atop a hollow threaded tube 118threadingly engaged on a lead screw 112 adapted to be rotated endlesslyin precise incremental fashion by an associated stepping motor 111. Oncea pack is partitioned, this subassembly will be understood as operativeto translate R/W transducer 15 onto the selected disk surface and trackwith shroud 13 serving to support the upper pack, guiding it over head15 while the pack is rotated.

Access door 110 is preferably mechanically linked to the disk loadingmechanism, including pivoting arm 107 and to a head/load interlockswitch, so that when the door is closed, the pack-rotating spindle-hubis automatically engaged with the pack and the drive subassemblypre-disposed for rotation thereof.

The basic functions of drive unit 100 will be recognized as to receiveand generate control signals, to spread the jacket and partition thepack (disk selection), to position the Read/Write head on selectedtracks of the selected flexible disk and to perform transducingoperations (e.g., write or read data) upon command from the dataprocessing controller. As workers in the art will know, positioning ofthe Read/Write head 15 (FIG. 6) is accomplished conventionally with thelead screw drive from linear stepping motor 111, with head 15 (mountedon the carriage coupled to be translated by this lead screw) stepped-inor -out, upon command, in incremental fashion by actuation of thestepper motor, rotating the lead screw a corresponding amount.

Partitioning is effected, preferably by a prescribed partitionsubassembly 140 including a select plunger (see plunger P in FIGS. 6 and11) disposed to be thrust upward through an accommodating aperture 123in working surface 125, upon actuation by an associated solenoid SOL.That is, as will be understood from FIG. 11, a "partition-signal"applied to energize the solenoid coil will act to pull a "clapper arm"A-1 down (against return spring 25) and throw an associatedplunger-linkage (arms A-2, A-3 pivotably mounted at pivot pv on thechassis) to throw plunger P upward as indicated in phantom in FIG. 11.This partition assembly will be recognized as particularly compatiblewith unit 100 to perform the select partitioning function of thejacket-encapsulated pack in the above indicated manner.

According to a related feature spindle drive motor 121 is adapted torotate the pack, disposed within the jacket J and engaged between hub109 and drive spindle 109-A, for transducing, as known in the art, aswell as to shift according to a related improvement feature, into asecond rotary-step mode for partition-positioning. That is, responsiveto a prescribed indexing control signal, motor 121 will digitally stepthe spindle and pack rotationally by a prescribed precise number ofintegral angular increments (digital signal) until "partition (angular)orientation" is achieved. This, in effect, the pack is made to step from"zero" or start radius (index hole) a prescribed number of "angularsteps" to thereby "count" its way, digitally, to a prescribed locatorhole position, whereat plunger P may thrust the pack to partition it andexpose the corresponding selected disk recording surface, as describedabove. For instance, in this embodiment it is convenient to step-rotatethe pack 1.8° per digital "stepping pulse" using a dual mode motor, sothat, with the locator holes (embodiment of FIG. 3) separated at 18°intervals, each rotary increment of 10 steps will carry the pack 18°,i.e., from one locator hole to the next.

Thereupon the transducer carriage (step translation motor 111) may beactivated to begin entry into the so-partitioned pack (from an outerreference position) while the partitioning plunger P is conjunctivelywithdrawn. Carriage-entry will thrust the transducer down upon theselected disk surface and will allow the distal end of the transducermount, and particularly shroud 13 mounted thereon, to contact and assumesupport of the upwardly-thrust portion of the pack. Shroud 13 willmaintain this contact, guidingly, while the pack is rotated and theRead/Write operations are performed.

That is, stepping motor 111 will translate the transducer head into thesplit pack and place it in compliant "gliding" contact with the selectedrecording surface of the disk for transducer operation (e.g., see U.S.Pat. No. 3,810,243 for typical operations). Upon completion of thetransducing operations, at one or several tracks, the head may bewithdrawn and a different recording surface (disk) accessed in anotherpartitioning cycle. The indicated novel partitioning and head mountarrangements will be seen as establishing stable, protected transducerpositioning at any selected disk surface of such a flexible pack.

According to this feature, the transducer is kept disk-engaged whilemoving from track to track on the selected recording surface, until itis entirely disengaged and withdrawn to the outer "rest position" (FIG.6). During partitioning and transducer entry, the rotary drive will, ofcourse, hold the pack in fixed position, being thereafter rotated (at360 rpm) for transducer operation with the "upper" deflected disks(above the selected one) being bent smoothly up over the mentionedshroud 13, as they pass over the transducer carriage 117.

Shroud 13 is configured, positioned and adapted, according to a relatedfeature, to smoothly, frictionlessly guide and urge these "upper disks"(above the split) thus upward, while they are so rotated to permit theunimpeded, non-damaging entry and withdrawal of the transducer mountinto, and out of, the split-pack (e.g., for Read/Write operations atdifferent disk tracks).

Workers in the art will appreciate that with such a select/partitioningmeans, operable in conjunction with such a hole-encoded flexible diskpack, the pack may be split to expose any selected disk, conveniently,yet precisely--e.g., simply rotating the pack to a prescribed angularposition corresponding with registry of the plunger with the associatedpartitioning pattern of locator-holes, then thrusting the plunger upthese locator-holes sufficient to admit entry of the transducer-shroud.Thereupon the rotation of the pack may be resumed.

Thus, for instance, when the "n^(th) " disk in a pack is selected, thepack will be rotated to "START" position (index hole reference), thenstepped by (n×18°) the angular increments corresponding with a rotationof the pack so that the associated locator-sites register with theplunger-locus. Up-thrust of the plunger will then lift all disks "aboven" away from the upper surface of "n" disk, exposing the latter fortransducer entry as described. For instance, as workers know, such astepping motor/lead screw arrangement can position the transducer headon any one of about 77 discrete track positions of a disk surface.Unexpectedly the "paper thin" disks can interfit slidingly whilerotating, yet appear to experience minimal frictional wear and damage atthe contacting surfaces, especially when protected by the mentionedflexible inter-liner means.

Jacket spreading

Drive unit 100 is provided with a jacket-opening and spreadingarrangement 130 (FIGS. 9, 10 and 12) which essentially comprises a pairof upward-thrusting plungers 31-A and 31-B and a related opposed pair ofdownward-thrusting plungers 33-A and 33-B (see also FIG. 8) coupled topivotable subassembly 136 so as to provide for functioning in theaforeindicated manner to automatically spread the entry slot edges ofjacket J (i.e., raise flap 21-T as indicated in phantom 21-T' and 31' inFIG. 12) to accommodate the partitioning of the pack inside and theentry of the transducer carriage 117 (FIGS. 9 and 10). As mentionedpreviously in connection with FIG. 8, the downward-thrusting plungers 33serve to pin the lower panel 21-B against forward guide platforms 125and 125' to thereby hold the jacket fixed when the disk pack is rotatedwithin the jacket.

Conclusion

In summary, workers in the art will recognize that the foregoingdescribed embodiments are well adapted to provide novel, unobviousimprovements in multi-disk media, as well as associated manufacturingmethods--especially for flexible disks--plus protective jacket means anddisk handling means including jacket spreaders and pack-partitioningarrangements according to the invention. Workers will also recognizethat, while a particular disk handling embodiment has been described,for clarity, the subject novel flexible cartridges (i.e., novel diskpacks and associated jacket) are entirely feasible for use with otherdisk handling arrangements, especially where these include the same orsimilar jacket spreading and pack-partitioning means. For instance,workers will recognize that, instead of the described partitioning meansoperating about the circumferential periphery of the disk pack, a likearrangement may be provided to operate closer to the center of the packsuch as upon like encoded holes arranged about an inner disk track.

That is, a series of hole-encoded collars may be substituted (nohole-encoding of disks), each supporting a respective disk in a pack andremovably coupled (e.g., by key-way means) to a common hub, or spindle,with a similar plunger means being arranged to be thrust up through thisstack of collars and deflect (upward) those "above" a given selecteddisk. Such an arrangement may be more apt for rigid disks.

Moreover, whereas the illustrative partitioning and/or jacket openingmeans are mechanical, it will be apparent that alternate means such aspneumatic or hydraulic partitioning means will in certain cases alsoserve. For instance, one could substitute a gas injection tube for themechanical plunger of the indicated partitioning arrangement and propela burst of pressurized gas up through a selected registered group oflocator-holes, as understood and appreciated by workers, under propercircumstances to (at least partially) partition the pack sufficient toallow transducer entry--in certain cases this will even reduceassociated abrasion and defacement of disk surfaces as well asaccelerate partitioning. One might introduce pressurized gas from insidea spindle hub adjacent the partitioning plane so that in case the disksare not rigid enough at their periphery once their hubs are raised tothe reference plane, application of a stream of pressurized gas can thenproceed radially out to maintain them raised. Then, once the head entersand the turntable begins to spin, much less gas pressure would probablybe required to maintain them in position above the partitioning plane asdesired, and certainly in conjunction with a supporting shroud. Further,in certain cases partitioning may be effected without completelyarresting the rotating disk pack (e.g., while quickly incrementing thepack in digital stepped fashion between R/W rotation sequences).Similarly, jacket spreading may be otherwise implemented within thebroad confines of the described concepts, for instance, by lateralintroduction of a pair of relatively horizontal vertically-expandablespreaders disposed relatively along the plane of an injected disk packto be automatically engaged, then expanded, as the jacket is thrust intothe disk drive assembly.

With the preferred embodiments of the invention thus described indetail, those skilled in the art will be able to contemplate certainmodifications in structure and/or method over that illustrated anddescribed, and/or contemplate the substitution of equivalent elementsfor some or all of those disclosed, while nonetheless practicing thenovel concepts described and claimed herein; accordingly, it is intendedthat all such modifications and substitutions be embraced insofar asthey fall within the spirit and scope of the appended claims.

What is claimed is:
 1. An automatic opener apparatus for opening ajacket container containing a concentric pack of partitionable flexiblerecording disks:said jacket comprising a pair of opposed relatively flatand flexible panels joined along three sides with a pack-admittingopening along the fourth side, each panel containing aperture meansadapted to accommodate disk partitioning means and jacket-opening thrustmeans; said apparatus comprising in combination: actuator means; andapair of opposed thrust means mounted and adapted to be automaticallyreciprocated, opposingly, toward and away from one another, by saidassociated actuator means; each of said pair of thrust means comprisingat least one rod, positioned and dimensioned to matingly pass through anassociated one of said aperture means in a respective jacket panel in alocation remote from said disk pack; said actuator means being arrangedto thrust the rods into the opposed jacket panels, through a respectiveaperture means, sufficient to part the jacket panels enough toaccommodate rotation, partition and transducing operations on the disksin the pack housed within the jacket.
 2. The combination as recited inclaim 1, wherein each jacket panel includes a pair of spreader-holesdisposed on opposite sides of the mid-point of said jacket opening;theholes in one panel being disposed adjacent said opening-side of thejacket and so as not to register with the holes in the other panel; andwherein each thrust means comprises a pair of like rods, disposed onopposite sides of the mid-point of said jacket opening, so as toregister with an associated pair of said holes in the adjacent one ofsaid panels.
 3. The combination as recited in claim 2, wherein one pairof said holes has a first diameter adapted to accommodate first spreaderrods of a like diameter and the other pair of holes has a seconddifferent diameter adapted to accommodate second spreader rods of a likediameter, different from that of said first rods.
 4. The combination asrecited in claim 3, wherein common linkage means is arranged to allowsaid actuator means to activate all rods.
 5. The combination as recitedin claim 4, wherein a first pair of said rods is disposed to pin theopposite jacket-panel fixedly to the apparatus.
 6. The combination asrecited in claim 5, wherein said actuator means is arranged andcontrolled to first actuate said first pair of rods; then later activatethe other pair of rods; thereby pinning one jacket panel, thendeflecting the other panel away.
 7. The combination as recited in claim6, wherein said linkage means is arranged to be automatically operatedby depressing means for affixing the pack within the given jacket onto arotatable turntable; and is also adapted to automatically operate saidopposing rod pairs stepwise, first thrusting one pair of rods in onedirection to pin the opposing jacket panel against fixed base means; andthen actuating the other, opposed pair of rods in the oppositedirection, and so urge the other panel away from said pinned paneladjacent said jacket mouth.